Williams Partners plans to use the net proceeds from the offering to fund a portion of its $750 million acquisition of certain ownership interests in Wamsutter LLC from Williams Cos Inc (WMB.N).

Lehman Brothers Inc, Citigroup Global Markets Inc and Merrill Lynch & Co are the joint book-running managers for the offering, the company said in a statement.

The underwriters have been granted a 30-day option to buy up to an additional 1.39 million common units to cover allotments.

Shares of the company were up about 2 percent at $41.13 in late electronic trade, after closing at $40.30 on the New York Stock Exchange. (Reporting by Shamik Paul in Bangalore; Editing by Deepak Kannan)